pg sql parser support insert

src/main/java/com/alibaba/druid/sql/ast/expr/SQLDefaultExpr.java

@@ -0,0 +1,25 @@
+package com.alibaba.druid.sql.ast.expr;
+
+import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+
+public class SQLDefaultExpr extends SQLLiteralExpr {
+
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    public boolean equals(Object o) {
+        return o instanceof SQLDefaultExpr;
+    }
+
+    @Override
+    public int hashCode() {
+        return 0;
+    }
+
+    @Override
+    protected void accept0(SQLASTVisitor visitor) {
+        visitor.visit(this);
+        visitor.endVisit(this);
+    }
+
+}

src/main/java/com/alibaba/druid/sql/ast/statement/SQLInsertStatement.java

@@ -27,12 +27,12 @@ import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 public class SQLInsertStatement extends SQLStatementImpl {
 
     private static final long   serialVersionUID = 1L;
-    private SQLName             tableName;
-    private String              alias;
+    protected SQLName             tableName;
+    protected String              alias;
 
-    private final List<SQLExpr> columns          = new ArrayList<SQLExpr>();
-    private ValuesClause        values;
-    private SQLSelect           query;
+    protected final List<SQLExpr> columns          = new ArrayList<SQLExpr>();
+    protected ValuesClause        values;
+    protected SQLSelect           query;
 
     public SQLInsertStatement(){
 

src/main/java/com/alibaba/druid/sql/ast/statement/SQLSelectStatement.java

@@ -22,7 +22,7 @@ public class SQLSelectStatement extends SQLStatementImpl {
 
     private static final long serialVersionUID = 1L;
 
-    private SQLSelect         select;
+    protected SQLSelect         select;
 
     public SQLSelectStatement(){